Tetrahedral ferric iron in phlogopite: Xanes and Mossbauer compared to single crystal X-ray data

This paper reports the results of a combined methodological study performed on tetraferriphlogopite from the Araxa carbonatite. We compare Mossbauer spectroscopy and X-ray absorption near-edge spectroscopy (XANES) results to previously reported single-crystal X-ray and electron microprobe analysis data (Cruciani & Zanazzi, 1994). The combined techniques provide evidence for the presence of a remarkable amount of tetrahedrally coordinated Fe3+ in this sample, and show that high OH content in tetraferriphlogopite is compatible with the large Fe2O3/FeO ratio inferred from the chemical and spectroscopic data.